Transesophageal echocardiography during pulmonary vein cryoballoon ablation for atrial fibrillation

Optimizing Imaging Techniques for Left Atrial Appendage Closure: Insights and Emerging Directions

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults and is associated with significant morbidity and mortality, including an increased risk of stroke, heart failure, dementia, and recurrent hospitalizations. As life expectancy rises, both the incidence and prevalence of AF continue to grow. Stroke prevention remains a cornerstone of AF management, with oral anticoagulation being the primary strategy to reduce thromboembolic risk. However, despite their advantages, direct oral anticoagulants do not completely eliminate the risk of bleeding complications. For patients in whom anticoagulation is contraindicated, poorly tolerated, or ineffective at preventing AF-related stroke, interventional alternatives have gained traction. The left atrial appendage (LAA), a primary site of thrombus formation in AF, can be occluded through a catheter-based procedure known as left atrial appendage closure (LAAC) or left atrial appendage occlusion (LAAO). This review aims to provide imaging specialists with a comprehensive understanding of their role in LAAC, underscoring the importance of a multidisciplinary approach to enhance patient selection, procedural success, and long-term efficacy.

Three-dimensional transesophageal echocardiographic evaluation of pulmonary vein anatomy prior to cryoablation: validation with cardiac CT scan

BACKGROUND

Anatomical characteristics of the left atrium and the pulmonary veins (PVs) may be relevant to the success rate of cryoballoon (CB)-ablation for atrial fibrillation (AF). Cardiac computed tomography (CCT) is considered as the gold standard for preablation imaging. Recently, three-dimensional transesophageal echocardiography (3DTOE) has been proposed for preprocedural assessment of cardiac structures relevant to CB-ablation. The accuracy of 3DTOE has not been validated by other imaging modalities.

OBJECTIVE

We prospectively evaluated the feasibility and the accuracy of 3DTOE imaging for the assessment of left atrial and PV structures prior to pulmonary vein isolation (PVI). In addition, CCT was used to validate the measurements obtained with 3DTOE.

METHODS

PV anatomy of 67 patients (59.7% men, mean age 58.5 ± 10.5 years) was assessed using both 3DTOE and CCT scan prior to PVI with the Arctic Front CB. The following parameters were measured bilaterally: PV ostium area (OA), the major and minor axis diameters of the ostium (a > b) and the width of the carina between the superior and the inferior PVs. In addition, the width of the left lateral ridge (LLR) between the left atrial appendage and the left superior PV. Evaluation of inter-technique agreement was based on linear regression with Pearson correlation coefficient (PCC) and Bland-Altman analysis of biases and limits of agreement.

RESULTS

Moderate positive correlation (PCC 0.5-0.7) was demonstrated between the two imaging methods for the right superior PV's OA and both axis diameters, the width of the LLR and left superior PV (LSPV) minor axis diameter (b) with limits of agreement ˂50% and no significant biases. Low positive or negligible correlation (PCC < 0.5) was found for both inferior PV parameters.

CONCLUSIONS

Detailed assessment of the right superior PV parameters, LLR and LSPV b is feasible with 3DTOE prior to AF ablation. This 3DTOE measurements demonstrated a clinically acceptable inter-technique agreement with those obtained with CCT.

Feasibility of Assessing Cryoballoon Pulmonary Vein Occlusion With Saline Injection and a Novel Mapping System

Thirty-eight patients had assessment of pulmonary vein occlusion with the dielectric mapping system and injection of saline as an alternative to contrast. Contrast injection was required to ascertain pulmonary vein occlusion in 31.6% (12 of 38) of subjects and 17.4% (27 of 155) of veins. No contrast was required in the last 13 subjects. In this single center study, a novel mapping-guided cryoablation approach appeared to minimize the use of contrast in pulmonary vein isolation for the treatment of atrial fibrillation.

Comparison of cryoballoon ablation for atrial fibrillation guided by real-time three-dimensional transesophageal echocardiography vs. contrast agent injection

Background:

Pulmonary vein (PV) occlusion generally depends on repetitive contrast agent injection when cryoballoon ablation for atrial fibrillation (AF). The present study was to compare the effect of cryoballoon ablation for AF guided by transesophageal echocardiography (TEE) vs. contrast agent injection.

Methods:

Eighty patients with paroxysmal AF (PAF) were enrolled in the study. About 40 patients underwent cryoballoon ablation without TEE (non-TEE group) and the other 40 underwent cryoballoon ablation with TEE for PV occlusion (TEE group). In the TEE group during the procedure, PVs were displayed in 3-dimensional images to guide the balloon to achieve PV occlusion. The patients were followed up at regularly scheduled visits every 2 months.

Results:

No differences were identified between the groups in regard to the procedure time and cryoablation time for each PV. The fluoroscopy time (6.7 ± 4.2 min vs. 17.9 ± 5.9 min, P < 0.05) and the amount of contrast agent (3.0 ± 5.1 mL vs.18.1 ± 3.4 mL, P < 0.05) in the TEE group were both less than the non-TEE group. At a mean of 13.0 ± 3.3 mon follow-up, success rates were similar between the TEE group and non-TEE group (77.5% vs. 80.0%, P = 0.88).

Conclusions:

Cryoballoon ablation with TEE for occlusion of the PV is both safe and effective. Less fluoroscopy time and a lower contrast agent load can be achieved with the help of TEE for PV occlusion during procedure.

Fluoroscopy-free cryoablation of atrial fibrillation guided solely by transoesophageal echocardiography: a case report

Background

Atrial fibrillation (AF) ablation has been shown to be possible using minimal or no fluoroscopic imaging for guidance. However, the techniques previously described focus on radiofrequency ablation or rely on the use of resource-heavy technology such as intra-cardiac echocardiography. We describe the first reported case in the literature of successful fluoroscopy-free AF cryoablation guided solely by transoesophageal echocardiography (TOE).

Case summary

A 65-year-old gentleman underwent cryoablation of paroxysmal AF using TOE guidance only with no use of fluoroscopy. Transoesophageal echocardiography was used in all stages of the procedure including guidance for transseptal puncture, ensuring balloon position in the pulmonary veins, and checking for post-procedure pericardial effusion. After 5 months of follow-up, the patient remains in sinus rhythm and has discontinued all antiarrhythmic and anticoagulant medication.

Discussion

This case demonstrates for the first time the feasibility of fluoroscopy-free cryoablation using only TOE for guidance.

Increased levels of red cell distribution width is correlated with presence of left atrial stasis in patients with non-valvular atrial fibrillation

OBJECTIVE:

Red cell distribution width (RDW) and neutrophil to lymphocyte ratio (NLR) have been found to be associated with non-valvular atrial fibrillation (AF) and cardiovascular diseases. However, correlation of these parameters with presence of left atrial (LA) thrombus and/or spontaneous echo contrast (SEC) in patients with non-valvular AF has not been clarified. This study was an investigation of correlation of RDW, NLR, and clinical risk factors with LA thrombus and dense SEC in patients with non-valvular AF in the Turkish population.

METHODS:

The demographic, laboratory, and echocardiographic properties of 619 non-valvular AF patients who underwent transesophageal echocardiography (TEE) examination before direct current cardioversion (DCCV) or AF ablation treatment were retrospectively investigated. Complete blood count (CBC) and biochemical parameters were studied 6 to 12 hours before TEE examination. Left atrial stasis (LAS) markers were noted as presence of left atrial/left atrial appendage (LA/LAA) thrombus or dense spontaneous echo contrast (DSEC).

RESULTS:

Total of 325 (52%) patients with LAS were compared with 294 patients (48%) without LAS. In the LAS group, there were 274 (84%) patients with LA/LAA thrombus and 51 (16%) patients with DSEC. LAS (+) group, values for RDW (14.85±1.48 vs. 13.77±1.30; p<0.01), NLR (2.38 [1.58], vs. 2.10 [1.35]; p<0.01) and C-reactive protein (0.95 [0.61] vs. 0.88 [0.60] mg/L; p<0.01) were significantly higher than seen in LAS (-) group. In multivariate regression analysis, increased level of RDW, age, male gender, heart failure, duration of AF >6 months, and international normalized ratio <2 were independently correlated with presence of LAS.

CONCLUSION:

Our study indicated that increased level of RDW is independently correlated with higher risk for development of LAS in patients with non-valvular AF.

Impact of transesophageal echocardiography during transseptal puncture on atrial fibrillation ablation

BACKGROUND

The aim of our study was to demonstrate the added value of routine transesophageal echocardiography (TEE) for correctly positioning the transseptal system in the fossa ovalis (FO), thus potentially preventing complications during fluoroscopy-guided transseptal puncture (TP), and for assessing the optimal puncture site within the FO according to the expected procedure type.

METHODS

Ninety-one patients undergoing pulmonary vein isolation (PVI) procedures by cryoballoon technique for drug-resistant paroxysmal or persistent atrial fibrillation (AF) were prospectively included. In 57 patients, the TP procedure was performed under fluoroscopic guidance and septal localization was confirmed by contrast injection through the needle and demonstration of septal tenting in both the anteroposterior and left lateral fluoroscopic projections. In 34 patients, TP was performed under TEE guidance and positioning was targeted to perform the TP procedure in the more anterior and inferior locations of the FO. Two patient groups were compared according to the incidence of complications directly attributable to transseptal catheterization, thromboembolic complications, recurrence rates after the ablation procedure, total procedural time, and fluoroscopy time.

RESULTS

Fluoroscopy time (p<0.001), total cryoablation time (p=0.002), and total procedural time (p<0.001) were shorter in the TEE-guided group. Left inferior pulmonary vein (LIPV) cryoablation time (p=0.007) and right inferior pulmonary vein (RIPV) cryoablation time (p=0.004) were significantly shorter and the number of applications to the LIPV (p=0.007) and RIPV (p=0.005) were significantly fewer in the TEE-guided group. Although there was a trend toward higher complication rates (20.6% vs. 31.6%, p=0.37) and recurrence rates (11.8% vs. 20.1%, p=0.26) in the fluoroscopy-guided group, the differences between the groups were not statistically significant.

CONCLUSIONS

TEE-guided TP for AF ablation is associated with shorter fluoroscopy time, shorter total cryoablation time, and shorter total procedural time. Importantly, TEE-guided TP facilitates cryoablation of the inferior pulmonary veins.